Spectrally- and polarization-resolved hyper-Rayleigh scattering measurements with polarization-insensitive detection

Cocrystals of 2-Aminopyrimidine with Boric Acid—Crystal Engineering of a Novel Nonlinear Optically (NLO) Active Crystal

“…This discourages the use of (2-AMP) 3 (H 3 BO 3 ) 2 crystals for technical applications. However, this newly discovered cocrystal of 2-aminopyrimidine with boric acid investigated in the present work provides a good example of the effectiveness of the crystal engineering approach that aimed to preserve the neutral 2-aminopyrimidine molecule (because of the amount of its total hyperpolarizability [1]) in a crystal structure with suitable (non-centrosymmetric) symmetry.…”

“…The Sellmeier coefficients for no are D1 = 2.654(1), D2 = 0.0327 (5), D3 = 0.063 (1), and D4 = 0.021(1) (sum of the squares of residuals ξ 2 = 7 × 10 -9 ). For ne, no fit was calculated; the dashed line in Figure 9b is a guide to the eye.…”

“…Within a very diverse family of studied organic molecules, 2-aminopyrimidine and its monocation represent simple heteroaromatic systems with highly delocalized π-electrons, which can act as promising carriers of NLO properties. In this context, we have previously demonstrated that the χ (2) NLO properties of these moieties are closely related to their protonation-the neutral 2-aminopyrimidine molecule has a 1.6 times higher total hyperpolarizability (β tot ) than its protonated monocation [1]. Considering these properties, crystal engineering has two main objectives-to incorporate the 2-aminopyrimidine moiety into molecular crystals with proper symmetry and to preserve it preferably as a neutral molecule.…”

Combining second harmonic generation and multiphoton excited photo-luminescence to investigate TiO2 nanoparticle powders

“…In the present study, we thus propose a third method to discriminate between SHG and MEPL contributions based on their distinctive polarization response. 22 This method is achieved by recording polarization resolved intensity graphs as the fundamental beam input polarization is rotated for a fixed output polarization. The corresponding polarization resolved graphs for the present TiO 2 powder study are displayed in Fig.…”